This invention relates to a process of preparing an electrode for an electrochemical cell with a porous support and an electrode obtained by said process. It more particularly but not exclusively relates to electrochemical cells having alkaline electrolytes with helical electrodes wherein at least one electrode comprises a porous metal support loaded with active material. This support displays a matrix structure similar to that of a sponge wherein the cells are interconnected in a three-dimensional matrix: It is referred to as "foamlike" material. The porosity of the foamlike material, exclusive of active material, is greater than 90%.
After the active material is loaded in the electrode, said electrode is compressed so as to adjust its thickness, to facilitate its assembly, thereby ensuring proper operation of the cell.
When two electrodes are helically wound with an interposed separator strip, it is necessary to employ a separator displaying a high tensile strength (greater than 50 N for a separator having a width of 5 cm for example). Such a separator is ordinarily composed of a sheet made of polyamide or polypropylene fibers having a diameter on the order of 25 micrometers.
For electrochemical reasons, it would be advantageous to create a separator having much finer fibers, that is, of a diameter on the order of 5 micrometers or even less. However, the tensile strength of such a separator would be much too low to enable it to be helically wound with two electrodes using known methods.